Ribbon lifting mechanism for a power-driven typewriter

ABSTRACT

A ribbon lifting mechanism in a power-driven typewriter moves a ribbon from an inoperative location to a printing location in response to the operation of an oscillating drive arrangement. The oscillating drive arrangement undergoes a cyclical operation with each actuation of a type key action and includes an eccentric cam for effecting movement of the ribbon to the printing location and another cam having a plurality of different camming lobes for effecting further incremental movements of the ribbon to slightly different positions at the printing location. Means are provided for effecting relative movement between the eccentric cam and the other cam to bring a different camming lobe into operation with each successive cyclical operation of the oscillating drive arrangement to effect movement of the ribbon to successively different positions at the printing location. To enable the ribbon lifting mechanism to be utilized in conjunction with a single element printer, the drive arrangement is carried on a bushing which is moveable along a drive shaft.

United States Patent [191 Hengelhaupt Jan. 1, 1974 RIBBON LIFTING MECHANISM FOR A POWER-DRIVEN TYPEWRITER Hans-Georg Hengelhaupt, Nurnberg, Germany [73] Assignee: Triumph Werke Nuernberg A.G.,

Nuernberg, Germany [22] Filed: July 19, 1972 [21] App]. No.: 273,104

[75] Inventor:

Primary ExaminerErnest T. Wright, Jr. Attorney-Joseph R. Spalla et a1.

[57] ABSTRACT A ribbon lifting mechanism in a power-driven typewriter moves a ribbon from an inoperative location to a printing location in response to the operation of an oscillating drive arrangement. The oscillating drive arrangement undergoes a cyclical operation with each actuation of a type key action and includes an eccentric cam for effecting movement of the ribbon to the printing location and another cam having a plurality of different camming lobes for effecting further incremental movements of the ribbon to slightly different positions at the printing location. Means are provided for effecting relative movement between the eccentric cam and the other cam to bring a different camming lobe into operation with each successive cyclical operation of the oscillating drive arrangement to effect movement of the ribbon to successively different positions at the printing location. To enable the ribbon lifting mechanism to be utilized in conjunction 'with a single element printer, the drive arrangement is lcan ried on a bushing which is moveable along a drive shaft.

7 Claims, 5 Drawing Figures PATENTEU 1 I974 SHEET 1 OF 2 RIBBUN LIFTING MECHANISM FOR A POWER-DRIVEN TYPEWRITER This invention relates to a ribbon lifting mechanism for a typewriter or similar business machine, and more particularly to a ribbon lifting mechanism for successively moving the ribbon to slightly different vertical positions to enable slightly different portions of the ribbon to be successively struck by a type head impacting against a paper platen, and thereby achieving greater utilization of the ribbon as it is fed through the machine.

In a typewriter or similar business machine, a ribbon lifting mechanism is provided for moving a ribbon from a rest location to a printing location adjacent a paper platen prior to the impacting of a type element against the paper platen. After the type element strikes the paper platen, the ribbon is returned from the printing location to the rest position, and this well known operation of the lifting mechanism occurs with each actuation of a type key action. The ribbon lifting mechanism is usually in the form of a pivotally supported lever carrying the ribbon in a fork at one end and including a drive arrangement for pivoting the lever'with every actuation of a type key action to lift the ribbon to the printing location. In a single element typewriter, the ribbon lifting mechanism must be carried along a line of type with the print element, and the drive arrangement for operating the lifting mechanism is usually in the form of an eccentric cam rotatably supported on a shaft which is driven in timed relation with the drive means for moving the print element in a printing action.

In the past, the typical ribbon lifting arrangement has lifted the ribbon to a single common printing location adjacent the paper platen with each actuation of a type key action. Such an arrangement has long been satisfactory when used with a reusable cloth ribbon which is fed baclr and forth through the machine by an appropriate ribbon winding mechanism. However, with the advent of non-reusable carbon typewriter ribbons, which are fed only once through a typewriter, it has become important to achieve greater utilization of the ribbon as it passes through the machine so as to minimize the expense of using such ribbons as well as to reduce the frequency with which new ribbons must be loaded into the machine. The need for greater utilization of the ribbon is particularly critical in a single element typewriter where the ribbon is carried on a movable carriage along with the print element, thereby strictly limiting the size of a ribbon holder or cartridge which may be used in the machine.

To achieve greater utilization of a carbon typewriter ribbon, as well as other types of ribbons, various arrangements have been provided for moving a ribbon to slightly different vertical positions at a printing location adjacent a paper platen so as to enable closely adjacent vertical portions of the ribbon to be struck by successive printing movements of a print element as the ribbon is fed through the machine. Such arrangements are shown in Czech Pat. Nos. 422,017 and 411,977, German Pat. No. 1,179,955 and U. S. Pat. Nos. 3,302,766 and 3,613,857. However, none of the prior art arrangements have been entirely satisfactory because they were not desirably compact, or comprised an undesirable number of components, or were not sufficiently reliable in operation.

Accordingly, an object of the present invention is to provide a reliable ribbon lifting mechanism for successively lifting the ribbon to slightly different vertical positions at a printing location with each successive actuation of a type key action so as to achieve greater utilization of the ribbon as the ribbon is fed through the machine.

Another object of the invention is to provide a desirably compact ribbon lifting mechanism for lifting a ribbon to slightly different vertical positions with each actuation of a type key action and which may desirably be mounted on a single drive shaft for movement on a carriage with a single element printer.

Another object of the present invention is to provide a ribbon lifting mechanism composed of a minimum number of parts which are arranged in a fixed configuration so as to maximize the reliability of the ribbon lifting mechanism.

Still other objects, features and advantages of the present invention will be apparent to those skilled in the art from a reading of the following detailed description of the invention, taken in conjunction with the accompanying drawing, wherein:

FIG. 1 is a diagrammatic view of a ribbon lifting mechanism constructed in accordance with the present invention;

FIG. 2 is a partial sectional view of the ribbon lifting mechanism shown in FIG. 1, and taken along the line 2-2 of FIG. 1;

FIG. 3 is an opposite side view of the drive arrangement of the ribbon lifting mechanism shown in FIG. 1 and illustrating the condition of the drive arrangement at the beginning of a cycle of a ribbon lifting operation;

FIG. 4 shows the drive arrangement of FIG. 3 after a half cycle of operation of the mechanism; and

FIG. 5 shows the drive arrangement of FIG. 3 after the ribbon lifting operation has been completed.

Referring now in detail to the figures in the drawing, there is shown a ribbon lifting arrangement, generally indicated 11, for use in a power driven typewriter for moving a ribbon from a rest or inoperative location to a printing location adjacent a paper platen, not shown, prior to a printing element, not shown, impacting against the paper platen. The ribbon lifting mechanism 11 is normally biased downwardly to the rest location,

and includes a drive arrangement, generally indicated 13, which is operated in response to the actuation of a type key action, not shown, to lift the ribbon to the printing location. To move the ribbon lifting mechanism 11 to the printing location in timed relation to the printing movement of a printing element, the drive arrangement 13 is keyed to a drive shaft 15 which undergoes a single revolution with each actuation of a type key action and which may also serve to drive the printing element. To facilitate the adoption of the ribbon lifting mechanism 11 to a single element printer, the ribbon lifting mechanism 1 1 may be suitably secured to a carriage carrying the printing element, and the drive arrangement 13 may be supported on a bushing 17 which is slidably carried along the drive shaft 15. The means for driving the drive shaft 15 as well as the type key action and other parts of the typewriter have been deleted from the present description, since they form no part of the present invention and may be desirably conventional.

As more particularly shown in FIGS. 1 and 2, the typewriter ribbon may be threaded in a conventional ribbon fork 19 at one end of a ribbon lever 21 which is pivotally supported about a rod 23 located on a carriage, and the ribbon lever 21 is connected in operating relationship to the drive arrangement 13 by a camming lever 25. As shown, the camming lever 25 is pivotally supported about a rod 27 which is carried by a supporting bracket 26 suitably secured to a wall 28 of the carriage, with one end of the camming lever 25 having a pin 29 received in a slot 31 of the ribbon lever 21, and with the other end of the camming lever 25 carrying a roller 33 engaging the drive arrangement 13. The ribbon fork 19 is normally biased to a rest or inoperative position by a spring 35 stretched between a suitable wall 28 of the carriage and the end of the camming lever 25 which is connected to the ribbon lever 21. In addition, the resilient spring 35 serves to maintain the roller 33 in cooperating engagement with the drive arrangement 13 to enable the camming lever 25 to undergo an oscillating movement during the operation of the drive arrangement 13.

To impart an oscillating drive to the camming lever 25 and hence move the ribbon to and from a printing location, the drive arrangement 13 includes an eccentric cam 37 which is rotatably driven a single revolution by the shaft in response to the actuation of a type key action. As shown, the eccentric cam 37 is carried by the bushing 17 and is drivingly connected to the drive shaft 15 by a key 41 which is slidably received in a slot 43 extending longitudinally in the drive shaft 15. A flange or sleeve portion 38 of the eccentric cam 37 is secured to the bushing 17 and to the key 41 by a ring 39 which is tightened about the sleeve portion 38. The key 41 and the bushing 17 carrying the other portions of the drive arrangement 13 are slidably moved along the drive shaft 15 as the carriage moves along the line of type during a printing operation.

To achieve greater utilization of a nonreusable ribbon by moving the ribbon to slightly different vertical positions at the printing location so as to enable closely adjacent vertical portions of the ribbon to be struck by successive printing actions, the drive arrangement 13 is provided with an additional camming means for slightly varying the oscillating movement imparted to the camming lever 25 with successive type key actuations. As more particular shown in FIGS. 35, the additional camming means is in the form of another cam 45 carried concentrically on the eccentric cam 37 and having a plurality of different camming lobes for engaging the roller 33 of the camming lever 25 and effecting movement of the ribbon to a plurality of slightly different positions at the printing location. The camming configuration of the multiple lobed cam 45 is superimposed on the camming configuration of the eccentric cam 37, and a different lobe of the cam 45 is brought into engagement with the roller 33 each time the lobe of the eccentric cam 37 rotates past the camming lever 25 so as to impart successively different oscillating movements to the ribbon lifting mechanism 11.

To bring a different lobe of the multiple lobed cam 45 into cooperation with the eccentric cam 37 as the lobe of the eccentric cam 37 rotates past the roller 33 of the camming lever 25, the multiple lobed cam 45 is supported for rotational movement about the eccentric cam 37, and means are provided for rotationally moving the multiple lobed cam 45 in time relation to the eccentric cam 37. As more particularly shown in FIGS. 1 and 2, the means for effecting relative rotational movement between the multiple lobed cam 45 and the eccentric cam 37 are in the form of an outer circular gear 47 associated with the cam 45 and having internal teeth meshing with the external teeth of an inner gear 49 carried on the drive shaft 15. The outer circular gear 47 is carried concentrically about the eccentric cam 37 and may be formed integrally with the cam 45 which may thus serve as the hub of the outer gear 47. The inner gear 49 is rotatably supported on the drive shaft 15 and is maintained stationary by an arm 51 suitably connecting it to a portion 52 of the carriage. The outer gear 47 is provided with a larger pitch circle than the inner gear 49, and when the eccentric cam 37 undergoes a cyclical rotational movement, it causes the outer gear 47 to roll around the stationary inner gear 49. Since the outer gear 47 has a larger pitch circle than the inner gear 49, it will undergo only a portion of a revolution with each cyclical rotation of the eccentric cam 37, thereby shifting the camming configuration of the multiple lobed cam 45 relative to the camming configuration of the eccentric cam 37 with each successive rotation thereof so as to vary the amplitude of the oscillating movement imparted to the camming lever 25.

To shift the configuration of the multiple lobed cam 45 in timed relation to the cyclical rotation of the eccentric carn 37, the camming configuration of the cam 45 is structured in accordance with the gear ratio between the outer and inner gears 47, 49 respectively. As shown in FIG. 1, the ratio of the number of gear teeth of the outer gear 47 to the inner gear 49 is selected as being six to five. As shown in FIGS. 3-5, the camming configuration of the multiple lobed cam 45 provides six complete variations relative to a common median radius, generally indicated 53, with each variation taking place within an angle of 60. Accordingly, with each complete revolution of the eccentric cam 37, the camming configuration of the multiple lobed cam 45 will be shifted by 60 to bring a different lobe into cooperation with the lobe of the eccentric cam 37. With the shaft 15 rotating in a clockwise direction, as viewed in FIG. 3, the eccentric cam 37 rotates through 180 to the position shown in FIG. 4 to operate the ribbon lifting mechanism to move the ribbon to the printing location. At the same time, the camming configuration of the multiple lobed cam 45 is shifted relative to the cam 37 to move the cam follower roller 33 from the median position 53 to a relief, or lobe, to effect movement of the ribbon to a particular position at the printing location. The continued rotation of the eccentric cam 37 through another I to the position shown in FIG. 5 causes the ribbon lifting mechanism to return to the rest position and effects a further shifting of the multiple lobed cam 45 to again bring the roller 33 to the median position 53.

From the foregoing, it will be apparent that with each successive cyclical rotation of the eccentric cam 37, the multiple lobed cam 45 will be shifted by 60 to bring a different lobe into engagement with the camming roller 33 and cause the ribbon to be moved to a correspondingly different position at the printing location. Although each of the six lobes of the multiple lobed cam 45 could be used to effect movement of the ribbon to six different positions, as shown in FIGS. 3-5 the lobes present a sequence of three different configurations which is repeated twice about the circumference of the cam 45. Also, the lobes of the multiple lobed cam 45 could be formed on the periphery of the outer gear d7 instead of on a separate cam 45 which, as shown, serves as the hub of the outer gear 47.

Although only a single preferred embodiment of the invention has been illustrated and described, it will be apparent to those skilled in the art that various modifications and improvements may be made. Accordingly, the scope of the invention is not to be limited by the illustrative embodiment, but only by the scope and spirit of the depending claims.

What is claimed is:

l. In a power-driven business machine having a ribbon lifting mechanism including an oscillating drive ar rangement operated in response to the actuation of a type key action, the combination comprising:

a drive shaft rotatably driven a single revolution with every actuation of a type key action,

an eccentric cam supported for rotation with said drive shaft for providing an oscillating drive for operating said ribbon lifting mechanism to move a ribbon from an inoperative location to a printing location during each single revolution of said drive shaft,

another carn having a plurality of different camming lobes formed thereon for providing a plurality of different incremental movements of said ribbon lifting mechanism to effect movement of the ribbon to a plurality of different positions at the printing location,

said other cam being supported by said eccentric cam for rotational movement relative thereto, and

moving means for effecting relative rotational move ment between said other cam and said eccentric cam to bring a different one of the plurality of camming lobes of said other cam into successive operation for effecting an incremental movement of said ribbon lifting mechanism to move a ribbon to successively different positions at the printing location with each operation of said ribbon lifting mechanism by the rotational movement of said eccentric cam.

2. in a business machine according to claim 1, wherein said means for effecting relative rotational movement between said eccentric cam and said other cam comprise:

a first gear supported for rotational movement relative to said shaft, and

a second gear associated with said other cam and cooperably engaged with said first gear for effecting rotational movement of said other cam relative to said eccentric cam as the rotational movement of said eccentric cam rotates said second gear about said first gear.

3. in a business machine according to claim 2:

said first gear being supported concentrically about the axis of said drive shaft and maintained stationary relative to the rotational movement of said drive shaft, and

said second gear being supported by said other cam for eccentric movement about the axis of said drive shaft.

4, In a business machine according to claim 3, the

combination further comprising:

a bushing carried by said drive shaft for rotational movement therewith and supported for axial movement along said drive shaft,

said first gear being carried by said bushing and supported for relative rotational movement thereto,

said eccentric cam being carried by said bushing for rotational movement therewith, and

connecting means for connecting said eccentric cam to said drive shaft for rotational movement therewith whereby said rotatably driven eccentric cam drives said second gear about said first gear to effect relative rotational movement between said eccentric cam and said other earn.

5. In a business machine according to claim 1, the

combination further comprising:

a bushing carried by said drive shaft and supported for axial movement along said drive shaft,

said bushing carrying said eccentric cam for rotation about the axis of said drive shaft,

means for connecting said eccentric cam to said drive shaft for rotational movement therewith, and

said moving means being carried by said bushing and supported for rotational movement relative to said drive shaft.

6. in a power-driven business machine having a ribbon lifting mechanism including an oscillating drive arrangement operated in response to the actuation of a type key action, the combination comprising:

a drive shaft rotatably driven a single revolution with every actuation of a type key action,

an eccentric cam supported for rotation with said drive shaft to provide an oscillating drive for operating said ribbon lifting mechanism to move a ribbon from an inoperative location to a printing location during a single revolution of said drive shaft,

a first gear carried by said eccentric cam and rotatable relative thereto,

said first gear having a plurality of different camming lobes formed thereon for providing a plurality of different incremental movements of said ribbon lifting mechanism to effect movement of the ribbon to a plurality of different positions at the printing location,

another gear supported concentrically about the axis of said drive shaft and maintained stationary for effecting relative rotational movement with said drive shaft, and i said other gear meshing with said first gear and hav ing a different pitch circle than said first gear for effecting relative rotational movement between said eccentric cam and said first gear upon rotation of said first gear by said eccentric cam so as to bring a different camming lobe into operation with each successive revolution of the drive shaft to effect successively different incremental movements of said ribbon lifting mechanism to move a ribbon to incrementally different positions at the printing location.

7. In a business machine according to claim 6, the

combination further comprising:

a bushing being carried by said drive shaft for rotational movement therewith and supported for axial movement along said drive shaft,

said eccentric cam being carried by said bushing for rotational movement therewith, and

said other gear being carried by said bushing and supported for rotational movement relative to said bushing for effecting relative movement between said eccentric cam and said first gear having said plurality of different camming lobes upon rotation of said first gear by said eccentric cam. 

1. In a power-driven business machine having a ribbon lifting mechanism including an oscillating drive arrangement operated in response to the actuation of a type key action, the combination comprising: a drive shaft rotatably driven a single revolution with every actuation of a type key action, an eccentric cam supported for rotation with said drive shaft for providing an oscillating drive for operating said ribbon lifting mechanism to move a ribbon from an inoperative location to a printing location during each single revolution of said drive shaft, another cam having a plurality of different camming lobes formed thereon for providing a plurality of different incremental movements of said ribbon lifting mechanism to effect movement of the ribbon to a plurality of different positions at the printing location, said other cam being supported by said eccentric cam for rotational movement relative thereto, and moving means for effecting relative rotational movement between said other cam and said eccentric cam to bring a different one of the plurality of camming lobes of said other cam into successive operation for effecting an incremental movement of said ribbon lifting mechanism to move a ribbon to successively different positions at the printing location with each operation of said ribbon lifting mechanism by the rotational movement of said eccentric cam.
 2. In a business machine according to claim 1, wherein said means for effecting relative rotational movement between said eccentric cam and said other cam comprise: a first gear supported for rotational movement relative to said shaft, and a second gear associated with said other cam and cooperably engaged with said first gear for effecting rotational movement of said other cam relative to said eccentric cam as the rotational movement of said eccentric cam rotates said second gear about said first gear.
 3. In a business machine according to claim 2: said first gear being supported concentrically about the axis of said drive shaft and maintained stationary relative to the rotational movement of said drive shaft, and said second gear being supported by said other cam for eccentric movement about the axis of said drive shaft.
 4. In a business machine according to claim 3, the combination further comprising: a bushing carried by said drive shaft for rotational movement therewith and supported for axial movement along said drive shaft, said first gear being carried by said bushing and supported for relative rotational movement thereto, said eccentric cam being carried by said bushing for rotational movement therewith, and connecting means for connecting said eccentric cam to said drive shaft for rotational movement therewith whereby said rotatably driven eccentric cam drives said second gear about said first gear to effect relative rotational movement between said eccentric cam and said other cam.
 5. In a business machine according to claim 1, the combination further comprising: a bushing carried by said drive shaft and supported for axial movement along said drive shaft, said bushing carrying said eccentric cam for rotation about the axis of said drive shaft, means for connecting said eccentric cam to said drive shaft for rotational movement therewith, and said moving means being carried by said bushing and supported for rotational movement relative to said drive shaft.
 6. In a power-driven business machine having a ribbon lifting mechanism including an oscillating drive arrangement operated in response to the actuation of a type key action, the combination comprising: a drive shaft rotatably driven a single revolution with every actuation of a type key action, an eccentric cam supportEd for rotation with said drive shaft to provide an oscillating drive for operating said ribbon lifting mechanism to move a ribbon from an inoperative location to a printing location during a single revolution of said drive shaft, a first gear carried by said eccentric cam and rotatable relative thereto, said first gear having a plurality of different camming lobes formed thereon for providing a plurality of different incremental movements of said ribbon lifting mechanism to effect movement of the ribbon to a plurality of different positions at the printing location, another gear supported concentrically about the axis of said drive shaft and maintained stationary for effecting relative rotational movement with said drive shaft, and said other gear meshing with said first gear and having a different pitch circle than said first gear for effecting relative rotational movement between said eccentric cam and said first gear upon rotation of said first gear by said eccentric cam so as to bring a different camming lobe into operation with each successive revolution of the drive shaft to effect successively different incremental movements of said ribbon lifting mechanism to move a ribbon to incrementally different positions at the printing location.
 7. In a business machine according to claim 6, the combination further comprising: a bushing being carried by said drive shaft for rotational movement therewith and supported for axial movement along said drive shaft, said eccentric cam being carried by said bushing for rotational movement therewith, and said other gear being carried by said bushing and supported for rotational movement relative to said bushing for effecting relative movement between said eccentric cam and said first gear having said plurality of different camming lobes upon rotation of said first gear by said eccentric cam. 